Pump construction



Aug. 26, 1958 A. H. WAKEMAN PUMP CONSTRUCTION Filed May 29, 1955 6% KWMWW Mn MM 2 United. States Patent. (1

. I Patented Aug. 26 195'8 2; pumpedthrough the pump housing 11 be' freefrom any deleteriouszsubstance: which might find' its way into the 2 848interior of said housing and contaminatethe product. The

PUMP CONSTRUCTION Alden H.Wakeman, Lakemills, Wis assignor to. TheCreamery Package Mfg. Company, Chicago, 111., a corporationof IllinoisApplication May 29, 1953, Serial No. 358 263...

2 Claims.- (Cl; 103-126) This inventionrelates to a pump-and moreparticularly to a positive pump whereinit is important that: theinterior thereof be free from any deleterious substance which mightcontaminate a product .while:being:pumped therethrough.

The problem of sealing the' periphery of? the shaft of'theimpeller in apump of this type againstsubstances such as air, oil and the likebeingdrawn into .thesuction side of the interior of the pump housing andcontaminating theproduct being pumped, has notheretofore' beensuccessfully overcome by use of the packingmaterials which are presentlyavailable. Various attempts have heretofore. been made to overcome thisproblem, butbecause of the cost, complexity, and bulkiness ofconstruction and the ineflicient operatiomof-the resultantpumps, suchattempts have met withonly partial success.

It is .one of the objects, therefore, of this inventionto provide a'pumpwherein the possibility of a deleterious substance beingdrawn intotheinterior of the pump-casingv fromaround the periphery of the.rotatingimpeller shaft has been completely eliminated.

It is a further object of this invention-to. provide a pump wherein theproduct being pumped, while. under high dischargepressure, functions asthe sealing means asrwellas the lubricant for the impeller shaft seal.and the impeller itself.

It is a further object of this invention" to providesa' pump which issimple and compact in construction, efiicient in operation,andiminimizes: service and maintenance: costs.

Further and additional. objects will appeart-from uthe description,accompanying drawing, and. appendedzclaims.

In. accordance with one embodiment of 'this invention, a' pump isprovided: comprising a: hollow r casing; having an inlet: port and an.outl'etaport, and: a pair of impellers rotatably mounted within; said;casing. and: disposed. intermediate said inlet and outlet L ports. Theperiphery: of each: impeller isldeformed *andhasvportions thereof: incontact with. the: interior of the casing. and the. other impeller; Theside surfaces-of the. casing. interiors cooperate with theadjacent'endrfaces of: each impeller. to

. shaperofthe'nubs. may vary without departing. from theform-azcavity-which encompasses the axis v.of; the impeller and is'disposedintermediate said 1 axis and ;the periphery of said impeller.The encompassingzcavity communicates with theoutletport of. said.vhollow casing to permit: a portion of the product being pumped underhighl'pressure to completely fill such cavity.

For a: more complete understanding of: this invention reference'shouldnow be made.- to .therdrawing wherein:

Figure- 1 is a vertical sectional view of-thepump;

Fig: 2 is a: right side. elevational view' of-the pump taken along line:2-2 of Fig. 1; .and

Fig. 3 is an enlarged. fragmentary. sectional view: ofthe-cavitieswformed between-the end faces of the impellers and, theadjacent side: surface of'thecompartment.

Referringnowto the drawings and more'particularly to Fig.. 1, apositivepump 10 is-..shown:. for usewins'instances where it is important thatthe product being pump housing 11-1 comprises two-compartments, 12 and13, formed: in the: interior thereof which are separated .16 formed: in*one side of the compartment and is discharged through outlet port 17formed in the opposite side of the compartment, see Fig. 2'. In thisinstance, impeller 14 is the driven. impeller and has the shaft 18thereof, which. extends through an aperture formed in partition 13f,rotatably 'supported withinthe housing 11 by. a. pair of anti-frictionbearings 20' and 21 arranged in; axially spacedrelation; One end 18w ofshaft 18 projects outward from. housing 11. through a suitable opening:and is adaptedto be driven by some external source of; power, not shown.Keyed: to shaft 18 and disposed;within compartment 13 is'a spur gear 22which is adapted. to meshs with. a like spur gear 23, the latterbeingkeyeditoxshaft 24' for i'mpellerlS, to effect simultaneousirotationof the twoimpellers. Shaft 24 likewise extends: through. asecond openingformed in partition 13" and 'is enclosed entirely within housing 11 andis supported by-apair of-uax-ially spacedanti-friction bearings 25' and26; Compartment 13 is normally filled or partially filled with alubricant which may be introduced into. the: compartment through a.-conduit, not shown,

.upper'side" of compartment 13. Both shafts 18 and 24 are surrounded bysealing rings 30 and 31, respectively, which: arexdisposed betweenanti-friction bearings 21.1 and 26 and the. partition-13, see- Fig. 1

Each of: the'impellers 14 and'=15: is of like construction andcomprisesa metallic. hub or core 32 which has the outer:periphery'thereof shapedso as'to form a plurality of symmetricallyarranged radially extending nubs 33 Whichtare adapted:to=mesh with oneanotherand impel the. productfrom. the low pressure side 12a to-the highpressure sideh12b' of: the compartment. The. number andscopeof.the-invention; The: core 32" is provided with a center bore,32awhich is internallysplined and adapted to receive: the, splined= end 18bor. 24b' of the shaft 18 on 24, respectively.. Encompassing the outerperiphery ofrcore 32, including the end faces. 32b thereof except for a.portion; surroundingthe center bore, is a plastic covering 1 3,4:ofpreferablyxrubber' or latex material which is notcorroded by or;does'not: contaminate the product being pumped.- and klikewise is.possessed; with good; wearing qualities. The nubs-33 of. the core 32with. the covering 34' thereon are of such dimension that the outer ends'thereof contact the: annular peripheral surface 37 of thecompartment12, asseen more clearlyin EigrZ. The portions 34a of the coating'34which sub 'stantially cover the end faces 32b: of core 321 are'provided;with? a marginal. boss 3412. which, in this instance, conformssubstantially -to the perimeter. of nubs 33; The marginal boss. 34b isadapted to slidably engage the opposing side surfaces 35 'and%36-Of thecompartment 12 when; the impellers. are being rotated. The areadelimitediby thewbosson each of the endfaces 32b of'theimpellerszformsva. cavity 43. which; is adapted to encompass theperiphery of shaft 18: or 24.

Formed: within. each. of the side. surfaces 35? and 36 of. compartment12: are elongated grooves-38 and 40, respectively, which are disposedWithin the high pressure side 12b of the compartment 12. The ends ofeach groove 38 and 40 are adapted to communicate with the cavity 43formed in each of the end faces of the impellers 14 and 15. A portion ofeach groove 38 and 40, disposed intermediate the ends thereof, isadapted to communicate with the high pressure side 12b of thecompartment 12. The purpose of grooves 38 and 40 is to allow a portionof the product, being pumped through compartment 12, to find its wayinto the cavities 43 and surround the peripheries of the impeller shafts18 and 24 with the product under high pressure. It will be noted in Fig.1 that an annular recess 44 is formed in the side surface 36 ofcompartment 12 and is adapted to encircle the periphery of the impellershaft 18 or 24. Disposed within each of the recesses 44 is an annularsealing piece 45 which is substantially V-shaped in cross-section. Theopen side of the sealing piece 45 is adjacent the end face of impeller14 or 15 and is adapted to communicate with the cavity 43 formed betweenthe end face of the impeller and the side surface 36 of the compartment.Upon the high pressure product becoming entrapped within the cavity, theproduct will cause the annular sealing piece 45 to expand a certainamount, thereby causing the piece 45 to function more effectively as aseal for the impeller shaft. By reason of the fact that the productunder high pressure is disposed within the cavities adjacent each of theend faces of the impeller, an effective seal is provided which preventsany foreign or deleterious substance such as oil, air and the like,being drawn into the suction side 12a of the compartment around theperiphery of each of the shafts. Furthermore, the product disposedwithin each of the cavities 43 acts as a lubricant between the end facesof the impellers and the corresponding side surfaces 35 and 36 of thecompartment 12. The compartment 12 has one side 41 thereof removable tofacilitate assembly of the impellers within the compartment 12. Thecover 41 is secured to the housing or casing 11 by nut and boltassemblies 42.

It is to be understood, of course, that the peripheral shape of each ofthe impellers may be varied without departing from the scope of thisinvention and that the marginal boss 34b may be of any shape so long asit encompasses the impeller shaft and is spaced therefrom and inaddition is disposed entirely within the periphery of the impeller.Furthermore, if so desired, the end faces of the impellers may be fiatand a boss, corresponding to the marginal boss 34b, be formed instead onthe side surfaces 35 and 36 of the compartment. In this latter instance,however, the bosses would have to be of such a shape that they would bedisposed at all times within the outer periphery of the impellers andspaced from the periphery of the impeller shaft. Thus, each side surfaceof the compartment would have formed thereon a boss for each impeller.The area delimited by the boss would communicate with the high pressureside 12b of the compartment 12 through a groove or any other suitableconduit. While the pump in this instance is directed to a unitcontaining two impellers, it is not to be limited thereto, as the novelconstruction may be incorporated in a pump having one or more impellersas well as single or multi stages.

Thus, a pump has been provided which is simple and compact inconstruction, durable and efficient in operation, and eliminatescompletely the possibility of foreign or deleterious substances findingtheir way into the interior of the pump casing from around the peripheryof the impeller shaft and contaminating the product being pumped.Furthermore, a pump has been provided which utilizes the product beingpumped to provide a seal for the impeller shaft and to provide alubricant for the end faces of the impeller.

While several embodiments of this invention have heretofore beendescribed, it will be understood, of course,

,4 that the invention is not to be limited thereto, since manymodifications may be made, and it is contemplated, therefore, by theappended claims, to cover any such modifications as fall within the truespirit and scope of this invention.

I claim:

1. A pump for circulating a liquid product, comprising a casing providedwith a chamber, an inlet port through which such product enters saidchamber, and an outlet port through which such product leaves saidchamber at a higher relative pressure; an impeller rotatably mountedwithin said chamber and disposed intermediate said inlet and outletports, said impeller having a peripheral configuration formed by anon-uniform radius about the rotary axis of said impeller and portionsof said periphery being in slidable contact with said chamber surface toimpel such product from said inlet port to said outlet port, an end faceof said impeller being provided with a resilient peripheral bossconforming to the contour of said impeller periphery and insubstantially continuous slidable engagement with the adjacent chambersurface and forming a cavity encompassing the rotary axis of saidimpeller and occupying a substantial portion of the area of saidimpeller end face; conduit means provided on said casing andcommunicating with the outlet port of said casing and said cavity andeffecting entrapment within said cavity of a portion of the dischargedproduct, the entrapped product being at a substantially uniform pressurethroughout said cavity and effecting lubrication between said end faceand the adjacent chamber surface; a drive shaft for said impellerprotruding from said end face and extending through a suitable boreformed in said chamber surface, the end of said bore adjacent saidchamber surface being provided with a counterbore in partial overlappingand communicating relation with said cavity; and a liquidpressure-responsive, shaft-encompassing element engaging the peripheryof said shaft and disposed within said counterbore and being deformableby the liquid pressure within said cavity to effect a liquid sealbetween said shaft and said bore.

2. A pump for circulating a liquid product, comprising a casing providedwith a chamber, an intake port through which such product enters saidchamber and a relatively spaced outlet port through which such productleaves said chamber at a higher relative pressure; a pair of impellersmounted within said chamber intermediate said inlet and outlet ports forrotation about substantially parallel relatively spaced shafts, eachshaft extending axially from the corresponding end face of said impellerand through one of a pair of relatively spaced bores formed in theadjacent chamber surface, the end of at least one of said bores adjacentsaid chamber surface being provided with a counterbore, the peripheralconfiguration of each of said impellers being formed by a non-uniformradius about the impeller rotary axis, portions of said impellerperipheries contacting one another and the chamber surface, when saidimpellers rotate, to effect impelling the product from the inlet port tothe outlet port, the end face of said impeller adjacent the counterborebeing provided with a resilient marginal boss conforming substantiallyto the contour of said impeller periphery, said peripheral boss being insubstantially continuous slidable contact with the adjacent chambersurface upon rotation of said impellers and forming a cavityencompassing the rotary axis of said impeller, said counterbore being inpartial overlapping and communicating relation with said cavity, conduitmeans provided on said casing and communicating with said outlet portand said cavity and effecting entrapment in said cavity of a portion ofthe discharged product at substantially a uniform pressure throughoutsaid cavity and effecting lubrication by the entrapped product betweensaid end face and the adjacent chamber surface, the cavity-formingsegment of said impeller end 5 face constituting a substantial portionof the area of said impeller end face; and a liquid pressure-responsiveshaft-encompassing element disposed Within said counterbore and beingdeformable by the liquid pressure within said cavity to efiect a liquidseal between the encompassed shaft and the corresponding casing bore.

References Cited in the file of this patent UNITED STATES PATENTS1,096,186 Nesmith May 12, 1914 1,451,859 Balcker Apr. 17, 1923 2,258,371Wernert Oct. 7, 1941 2,455,194 Rumsey Nov. 30, 1948

